The Professor drags the crew into the past to root out a family traitor, leading to some unexpected changes to their future.

Time travel and "Futurama" has been a winning combination before, so it's understandable that the show's writers are going back to that well in "All the Presidents' Heads." The story finds Professor Farnsworth (Billy West) obsessed with tracking his family tree, only nominally including Fry as his distant uncle. The three ancestors cited by the Professor were even real people, so score one for the writer!

It sometimes seems as if even the characters on "Futurama" are aware that their lives are little more than set ups for a joke. When Fry rushes out to his new night job to pay for the coffee it takes to keep him awake for his night job, Leela (Katey Sagal) can't even explain why that doesn't make sense before he's out the door. As it happens, Fry is now working as a guard at the Head Museum, where the Hall of Former U.S. Presidents (now living as heads in jars) goad him into throwing a party with all of his friends.

The personalities of the Presedents' heads may not be entirely accurate (unless there's some proof out there that James Madison had a fetish for bare elbows), but there were enough historical jokes to make it an enjoyable sequence. And while attempting to show off his family tree, the Professor gets some bad news from George Washington. One of the Professor's ancestors, David Farnsworth was a notorious counterfeiter and a traitor to the colonies during the Revolutionary War. Thus the Professor drinks from the special time infused liquid keeping Washington alive in a jar and he somehow brings the crew back to the past in order to prevent his ancestor for leaving him a bad name.

To recap, the crew literally travel in time by drinking fluid from the head jars. Okay… why not? That seemed to the prevailing theme of the episode. If there was no way to explain Bender's presence, just have the residents of the past believe that he's a walking still, a chamber pot or even a cannon, among other things. That was actually a very effective recurring gag, as were the crew's costumes changing to match the era. Leela's explanation that she was from Peru was another winner.

The Planet Express crew eventually teams up with the brilliant and lecherous Ben Franklin to track down and stop David Farnsworth. But in the process, Fry accidentally messes up Paul Revere's famous ride and he "really screws the granny this time;" which was easily the best line of the episode. I think that's a line that only works on this show.

Once back in the future, the crew finds that America lost the Revolutionary War and David's actions in the past made the Professor one of the richest men in "West Britannica." The thoroughly "English" incarnations of the crew (seen above) were a blast, horribly fake accents and all. The overly British future even gave us a terrific cameo by the fourth Doctor and the TARDIS from "Doctor Who."

The problem is that the episode runs out of steam pretty quickly once the action shifts back to the new future. There's a lot of potential in watching the characters explore the changes to their timeline, but it felt sluggish compared to the majority of the episode. "All the Presidents' Heads" is similar to "Neutopia" in that it spends almost the entire episode setting up a promising premise without really living up to it. Even the resolution of the plot seems like an afterthought as things snapped back to normal.

I'd be lying if I said that I didn't enjoy this episode. It was good… or at least good enough. With a few more tweaks, it might have even been one of the best of the series. Instead, it's more of a middle of the road episode for "Futurama." But an average episode of "Futurama" is still better than almost anything else.